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Short behind dash - burnt out MMDC?

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'06 Wakesetter VLX.

I have my stereo wired to one of the ACC switches (flick the switch and it fires up the stereo).
There are two ACC switches on the left hand side of the dash right next to each other. I grabbed 12V positive from the ACC switch on the left because the switch on the right wasn't wired in. This was wired from the factor harness and had a white wire with red tracer.

Today I noticed I had a loose connection on my switch for the positive. While putting it back on my pliers must have slipped and I hit some metal to ground it out? When this happened the alarm for the depth sounder started going off constantly. Turning off the boat shut that off but now I have no display/gauges and no start on the boat. Also the ACC switches don't light up when on anymore (no power to them now?) All breakers under the arm rest are fine. All other power functions to the boat are unaffected.


Tracing the wire back and it goes straight to the MMDC (same colour/tracer wire comes out of the harness and goes into the depth sounder unit too). So I suppose I shorted out/burnt out the MMDC?

Few questions:

1) Does an MMDC need programming or can it just simply be swapped in and run?

2) I'm assuming that 12V positive comes from the MMDC and isn't from somewhere else on the harness so no voltage on this indicates the MMDC is no longer sending 12V + as it is dead

3) Can a dead MMDC cause a no start?

4) Is there some breaker or fuse I am not checking?


Terrible photo but here is the back of the switches:


Diagram of that photo:


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After rooting around in the engine compartment I finally found the breaker switch beside the ECU.

Weirdly enough it didn't feel tripped? It was firm and didn't push in or anything. Regardless I gave it some pushing and managed to get the boat to crank.
SO looks like a bad MDC won't cause a no-start. I still don't have gauges but I ordered a new MDC (luckily my boat uses the Mini version which is only $100).


That answers my questions 3 + 4.

Still very concerned as to whether or not my new MDC needs a program?

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I know the older MDC-1600 units don't require programming so I'm assuming the same for the mini. Also, I've read on here that there are two inline fuses for the MDC - one on the incoming 12v to the box and one going to the gauges. Not sure that these fuses are on every boat but might be worth double checking.

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6 hours ago, drh said:

 two inline fuses for the MDC - one on the incoming 12v to the box and one going to the gauges. Not sure that these fuses are on every boat but might be worth double checking.

Yeah, I've seen people discussing that online, but it seems like those are on boats with the 1600.
I can't see any fuses, but the harness is so bundled up tightly and immediately disappears behind the arm rest. So I guess if there are fuses on this they are extremely well hidden. Would be nice if Malibu provided wiring diagrams for this...

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